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Marni Kahn 1A
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Postby Marni Kahn 1A » Wed Oct 23, 2019 4:29 pm

Why are Helium, Lithium, Beryllium, and Hydrogen exceptions to the lewis dot structure in terms of creating an octet for each atom

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Re: Exceptions

Postby EMurphy_2L » Wed Oct 23, 2019 4:35 pm

Because they would need an unrealistic amount of electrons to create an octet. H would need 7 electrons, He would need 6, Li would need 5, Be would need 4. It is unlikely that any atom in any bond would share or recieve this many electrons. For other atoms with low valence electrons (like Na or Ca that also would need to gain 7 or 6 electrons) they just become cations-- they lose electrons. But for the first few elements, there is no *previous* noble gas that they could mimic the octet of.
Hope this makes sense!

Qiu Ya Wu 4I
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Re: Exceptions

Postby Qiu Ya Wu 4I » Wed Oct 23, 2019 4:36 pm

I believe that it would just be far more reasonable for these atoms to gain/lose electrons to fulfill the 1s shell rather than gaining all those excess electrons to fill the entire 2nd shell.
Last edited by Qiu Ya Wu 4I on Wed Oct 23, 2019 4:38 pm, edited 1 time in total.

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Re: Exceptions

Postby kpang_4H » Wed Oct 23, 2019 4:37 pm

They only need 2 electrons to be satisfied, so if lithium loses an electron it will be stable.

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